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Mapping Ground Zero with Lasers

Posted by michael on from the search-and-rescue dept.

securitas writes: "Amazing how the WTC disaster has shone a light on technology (pun intended). LIDAR (Light Detecting and Ranging) is the optical equivalent of RADAR. It's being used to create hyper-detailed maps of the WTC disaster site from an altitude of 5000 feet to detect shifts in the rubble as well as areas in danger of collapse."

3 of 97 comments (clear)

  1. Re:maybe offtopic by budgenator · · Score: 5, Informative

    not sure about any real attempt to dig it out, there's lots of problems there.
    First the WTC was built in a "bathtub" because the foundation is below sea level so if the bathtub is cracked mud could rush in and de-stablize near by structures like subways, utility conduits and other building foundations. The WTC actualy re-inforced the tub internaly to prevent its colapse; now its rubble. To do this there is talk that they may have to drill through the tub and sink tie-backs into the bedrock or build cross-bracing beams and remove the rummble between the openings.
    FYI Infrared lasers LIDAR is helpful here because of its excellent smoke-haze penetration and higher detail. Microwave side-looking radar might work but I think that the dust would either block or distorte the data. The sonar is probably used to probe the columns in near by buildings for hidden internal damage

    --
    Apocalypse Cancelled, Sorry, No Ticket Refunds
  2. Terrible Sense of Levity by brianvan · · Score: 4, Insightful

    I know Michael got reamed for this yesterday, but this once again is a story that uses an inappropriate introduction... with words like "nifty" and "(pun intended)" to refer to something regarding this tragedy...

    I mean, I'm not one to be oversensitive, but come on people... I think that you disrespect the dead and the affected when you use cavalier words while referring to this situation. I only live 5 miles from Ground Zero and I saw the towers collapse with my own eyes. This makes me no more or less affected than any other American (save for those who lost a loved one in the disaster), but for a story poster to consistently make the same error in judgement like this obviously shows something about his regard for human life, for American pride, and for the people around him that are deeply affected by this terrible situation.

    I ask not that we refrain from bringing it up, as I'm very proud of Slashdot in general for its coverage of this situation. But, to repeat the point from yesterday, there is nothing "nifty" about 6,700 innocent Americans dying in the most horrible way possible at the hands of a few highly irrational people... people whose peers live among us today waiting to give us our next big tragedy, our next week of continuous news coverage, our next spilling of innocent blood.

    I mean, I don't want to be too dramatic, but our American flags don't just cheer us up and bring us together... they remind us of our freedom and the horrible things that happened because we insisted on having it. It may be 13 days later, but it's still a horrible thing. Please treat it accordingly.

  3. Re:how is this done? by mpe · · Score: 4, Informative

    How do they monitor the site constatly from 5000 feet? is there a plane constantly circling around the site or is it done by a sort of balloon? can't this monitoring be achieved by satellites?

    A satellite can't monitor such an area constantly, since Manhatten isn't on the equator.
    The easiest way would be a teathered balloon.